join

join

 [

options

] 

file1

 

file2

Join the common lines of sorted file1 and sorted file2 . (Read standard input if file1 is - .) The output contains the common field and the remainder of each line from file1 and file2 . In the options below, n can be 1 or 2, referring to file1 or file2 .

Options

-a n

List unpairable lines in file n (or both if n is omitted).

-e s

Replace any empty output field with the string s .

-j n m

Join on the m th field of file n (or both files if n is omitted).

-o n.m

Each output line contains fields specified by file number n and field number m . The common field is suppressed unless requested.

-t c

Use character c as field separator for input and output.

Examples

Assuming the following input files:

%
 

cat score

 olga    81      91 rene    82      92 zack    83      93 
%
 

cat grade

 olga    B       A rene    B       A

List scores followed by grades, including unmatched lines:

%
 

join -a score grade

 olga 81 91 B A rene 82 92 B A zack 83 93

Pair each score with its grade:

%
 

join -o 1.1 1.2 2.2 1.3 2.3 score grade

 olga 81 B 91 A rene 82 B 92 A